During the operation of a hydrogen-based fuel cell, there is an accumulation of impurities in the anode side due to cross-leaks and diffusion through membrane from the cathode side of the fuel cell. One of the methods which is used to reduce the impact of such accumulation is purging of the anode loop, wherein purging involves the removal of hydrogen from the anode loop. As can be appreciated by one skilled in the art, this can be done, for example, by the low cell purge, the differential pressure purge and the time-based purge, the latter of which is a preventive purge.
One of the problems associated with the time-based purge is determining the time and duration of the purge. The higher the load on the fuel cell, the more rapidly impurities accumulate in the anode loop of the fuel cell. Therefore, a time-based purge method is needed which is based on the average load on a fuel cell during a fuel cell operating cycle, and therefore, removes impurities from the anode loop in an efficient and timely manner.